A PREDICTIVE MODEL FOR AGGRESSIVE NON-HODGKINS-LYMPHOMA

Background. Although many patients with intermediate-grade or high-gra de (aggressive) non-Hodgkin's lymphoma are cured by combination chemot herapy, the remainder are not cured and ultimately die of their diseas e. The Ann Arbor classification, used to determine the stage of this d isease, does not consistently distinguish between patients with differ ent long-term prognoses. This project was undertaken to develop a mode l for predicting outcome in patients with aggressive non-Hodgkin's lym phoma on the basis of the patients' clinical characteristics before tr eatment. Methods. Adults with aggressive non-Hodgkin's lymphoma from 1 6 institutions and cooperative groups in the United States, Europe, an d Canada who were treated between 1982 and 1987 with combination-chemo therapy regimens containing doxorubicin were evaluated for clinical fe atures predictive of overall survival and relapse-free survival. Featu res that remained independently significant in step-down regression an alyses of survival were incorporated into models that identified group s of patients of all ages and groups of patients no more than 60 years old with different risks of death. Results. In 2031 patients of all a ges, our model, based on age, tumor stage, serum lactate dehydrogenase concentration, performance status, and number of extranodal disease s ites, identified four risk groups with predicted five-year survival ra tes of 73 percent, 51 percent, 43 percent, and 26 percent. In 1274 pat ients 60 or younger, an age-adjusted model based on tumor stage, lacta te dehydrogenase level, and performance status identified four risk gr oups with predicted five-year survival rates of 83 percent, 69 percent , 46 percent, and 32 percent. In both models, the increased risk of de ath was due to both a lower rate of complete responses and a higher ra te of relapse from complete response. These two indexes, called the in ternational index and the age-adjusted international index, were signi ficantly more accurate than the Ann Arbor classification in predicting long-term survival. Conclusions. The international index and the age- adjusted international index should be used in the design of future th erapeutic trials in patients with aggressive non-Hodgkin's lymphoma an d in the selection of appropriate therapeutic approaches for individua l patients.